Erectile dysfunction (ED), commonly referred to as impotence, is defined as the persistent inability to achieve and maintain an erection of the penis sufficient for satisfactory sexual intercourse for the past 3 months. Although ED is not a life-threatening disease, it is closely related to the patient’s quality of life, sexual partnership, family stability, and is an early warning sign of many somatic diseases. The causes of erectile dysfunction are mainly categorized into two main groups: psychological and organic. Psychological factors mainly include: ① lack of sexual knowledge; ② mental trauma; ③ husband and wife relationship, social relationship disharmony. Organic factors mainly include: ① age; ② systemic diseases, including cardiovascular disease, endocrine disease, genitourinary disease, neurological disease, blood disease, chronic liver and kidney insufficiency, etc.; ③ drugs, including anti-hypertensive drugs, hormonal drugs, anti-psychotics, etc.; ④ habits, including long-term smoking, alcoholism and drug abuse, etc.; ⑤ traumas and surgery.